A hammer mechanism, including a piston, a connecting rod as well as a striker, may be situated within the transmission housing of a typical hand-held power tool. These are lubricated by a lubricant present in the transmission housing, for example a transmission oil, for the purpose of interacting preferably with little friction. The lubricant is typically introduced into the transmission housing via the transmission housing opening. To prevent the lubricant from exiting the transmission housing, the transmission housing opening is closed by a base body of a hand-held power tool transmission closure. The base body may be designed as a plug.